Accurate Evaluation of the Loss Coefficient and the Entrance Length of the Inlet Region of a Channel

Sadri, R.; Floryan, J. M.

doi:10.1115/1.1493813

Cited by 26 publications

(16 citation statements)

References 24 publications

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“…In addition, the entrance pressure drop is calculated using correlations developed by Sadri and Floryan [42], but is negligible compared to the friction losses over the length of the stack because L h.…”

Section: Appendix F Spacer Propertiesmentioning

confidence: 99%

Optimal design and operation of electrodialysis for brackish-water desalination and for high-salinity brine concentration

et al. 2017

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Electrodialysis (ED) is a desalination technology that has been deployed commercially for decades. However, few studies in the literature have looked at the optimal design and operation of these systems, especially for the concentration of high-salinity brines. In this paper, a set of constraints is defined to allow a fair comparison between different system sizes, designs, and operating conditions. The design and operation of ED are studied for the applications of brackish-water desalination and of high-salinity brine concentration for a fixed system size. The set of variables that determine the power consumption of a fixed-size system is reduced to include only the channel height and the velocity, with all the other design and operation variables depending on these two variables. After studying the minimization of power consumption for a fixed system size, the minimum costs associated with the different system sizes are studied, and the differing trends in brackish-water and high-salinity applications are compared. Finally this paper presents the effect of the cost modeling parameters on the trends of the optimal system size, current density, length, channel height, and velocity for the two applications studied.

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Section: Appendix F Spacer Propertiesmentioning

confidence: 99%

Optimal design and operation of electrodialysis for brackish-water desalination and for high-salinity brine concentration

et al. 2017

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“…Given that medium flow supplies oxygen to the cells, the flow distribution through the channels is critical for proper oxygenation. The pressure drop due to undeveloped flow at the entrance of a horizontal channel can be combined with the pressure drop caused by a vena contracta (geometry effect) at the entrance ( (Sadri and Floryan, 2002). We used this model to estimate the pressure drop at the entrance of the horizontal channels on the cell-seeded substrate.…”

Section: Flow Rate Distributionmentioning

confidence: 99%

Radial flow hepatocyte bioreactor using stacked microfabricated grooved substrates

Park

Berthiaume

et al. 2007

Biotech & Bioengineering

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Bioartificial liver (BAL) devices with fully functioning hepatocytes have the potential to provide temporary hepatic support for patients with liver failure. The goal of this study was to optimize the flow environment for the cultured hepatocytes in a stacked substrate, radial flow bioreactor. Photolithographic techniques were used to microfabricate concentric grooves onto the underlying glass substrates. The microgrooves served to protect the seeded hepatocytes from the high shear stresses caused by the volumetric flow rates necessary for adequate convective oxygen delivery. Finite element analysis was used to analyze the shear stresses and oxygen concentrations in the bioreactor. By employing high volumetric flow rates, sufficient oxygen supply to the hepatocytes was possible without an integrated oxygen permeable membrane. To implement this concept, 18 microgrooved glass substrates, seeded with rat hepatocytes cocultured with 3T3-J2 fibroblasts, were stacked in the bioreactor, creating a channel height of 100 microm between each substrate. In this bioreactor configuration, liver-specific functions (i.e., albumin and urea synthesis rates) of the hepatocytes remained stable over 5 days of perfusion, and were significantly increased compared to those in the radial flow bioreactor with stacked substrates without microgrooves. This study suggests that this radial flow bioreactor with stacked microgrooved substrates is scalable and may have potential as a BAL device in the treatment of liver failure.

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“…As has already been demonstrated in the past, the values of the shear stress near the wall have a decisive impact on various transfer processes [1], on sedimentation rate of particles [2], on physiological changes in blood-vessel walls [3], on investigating loss factors in pipeline [4], on development of velocity profiles after entering the pipeline [5,6,7], etc. One of the most progressive is the method of artificial cultivation of human tissue grafts in so-called bio-reactors [8], in which a specific shear stress on walls of the cores (where the grafts grow) is being artificially maintained.…”

Section: Introductionmentioning

confidence: 99%

The Measurement of Wall Shear Stress in the Low-Viscosity Liquids

Schmirler

Matěcha

Netřebská

et al. 2013

EPJ Web of Conferences

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Abstract. The paper is focused on quantitative evaluation of the value of the wall shear stress in liquids with low viscosity by means of the method of the hot film anemometry in a laminar and turbulent flow. Two systems for calibration of probes are described in the paper. The first of these uses an innovative method of probe calibration using a known flow in a cylindrical gap between two concentric cylinders where the inner cylinder is rotated and a known velocity profile and shear rate, or shear stress profile, is calculated from the NavierStokes equations. This method is usable for lower values of the wall shear stress, particularly in the areas of laminar flow. The second method is based on direct calibration of the probes using a floating element. This element, with a size of 120x80 mm, is part of a rectangular channel. This method of calibration enables the probe calibration at higher shear rates and is applicable also to turbulent flow. Values obtained from both calibration methods are also compared with results of measurements of the wall shear stress in a straight smooth channel for a certain range of Reynolds numbers and compared with analytical calculations. The accuracy of the method and the influence of various parasitic phenomena on the accuracy of the measured results were discussed. The paper describes in particular the influence of geometric purity of the probe location, the impact of various transfer phenomena, requirements for the measured liquid and layout of the experiment.

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Accurate Evaluation of the Loss Coefficient and the Entrance Length of the Inlet Region of a Channel

Abstract: Evaluations of loss coefficient and entrance length in the inlet region of a channel are presented. Correlations and numerical values of these quantities are provided for Reynolds number ranging from 0.01 to 2200. The results provide an accurate benchmark for engineering design.

Cited by 26 publications

References 24 publications

Optimal design and operation of electrodialysis for brackish-water desalination and for high-salinity brine concentration

Optimal design and operation of electrodialysis for brackish-water desalination and for high-salinity brine concentration

Radial flow hepatocyte bioreactor using stacked microfabricated grooved substrates

The Measurement of Wall Shear Stress in the Low-Viscosity Liquids

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